History

Mathieu Benoit eb5e607e1e [FIX] proxmox : le pont NAT s'écrivait avant de savoir si le NAT existe « Table does not exist » : six lignes d'iptables et « code de retour 1 », après avoir déjà posé la strophe dans /etc/network/interfaces. Rien dans ce bruit ne dit qu'il faut redémarrer. L'hôte tournait le noyau cloud de Debian, qui est dépouillé de tout netfilter — aucun module NAT, ni legacy ni nft. Et le cas n'a rien d'exotique : c'est notre propre install_proxmox.sh qui le produit. Il pose le noyau Proxmox sans redémarrer, à raison — lancé par ssh, un reboot couperait la session et ferait passer l'installation pour un échec. Une Proxmox imbriquée fraîchement installée est donc TOUJOURS dans cet état. L'avertissement sur le noyau existait déjà, mais à la CONFIRMATION de l'hôte, et l'hôte est ensuite mémorisé : on revient des jours plus tard créer un pont, et plus personne ne rappelle rien. Le garde va donc là où la conséquence tombe, et AVANT toute écriture. Il interroge la table NAT elle-même et non le NOM du noyau — « -pve » est un indice, pas une preuve — puis nomme le noyau en cours, celui qui est posé, et la commande qui règle l'affaire. Le sommaire de déploiement le dit désormais aussi, tant qu'on lit encore l'écran plutôt qu'au bout d'un journal d'une heure. --- EN --- "Table does not exist": six lines of iptables and "exit code 1", after the stanza had already been written into /etc/network/interfaces. Nothing in that noise says a reboot is needed. The host was running Debian's cloud kernel, stripped of all netfilter — no NAT module, legacy or nft. And the case is not exotic: our own install_proxmox.sh produces it. It installs the Proxmox kernel without rebooting, rightly — run over ssh, a reboot would cut the session and make the install look failed. A freshly installed nested Proxmox is therefore ALWAYS in this state. The kernel warning already existed, but at host CONFIRMATION, and the host is then remembered: you come back days later to create a bridge and nothing reminds you. So the guard moves to where the consequence lands, and BEFORE any write. It asks the NAT table itself rather than the kernel's NAME — "-pve" is a hint, not a proof — then names the running kernel, the installed one, and the command that settles it. The deployment summary now says it too, while the screen is still being read rather than at the end of an hour-long log. Assisted-by: Claude Opus 5		2026-08-25 03:31:12 -04:00
..
install_proxmox.sh	[ADD] proxmox : déployer des VM sur un hôte Proxmox distant	2026-08-23 05:54:38 -04:00
proxmox_deploy.py	[FIX] proxmox : le pont NAT s'écrivait avant de savoir si le NAT existe	2026-08-25 03:31:12 -04:00
README.base.md	[ADD] proxmox : déployer des VM sur un hôte Proxmox distant	2026-08-23 05:54:38 -04:00
README.fr.md	[ADD] proxmox : déployer des VM sur un hôte Proxmox distant	2026-08-23 05:54:38 -04:00
README.md	[ADD] proxmox : déployer des VM sur un hôte Proxmox distant	2026-08-23 05:54:38 -04:00

README.md

Deploying VMs on a Proxmox VE host

Two different things live in this directory:

install_proxmox.sh turns a Debian into a Proxmox hypervisor. See script/qemu/README.md, which documents the proxmox distro of the deployment catalog.
proxmox_deploy.py deploys VMs on such a host, from TODO › Execute › Deploy › Proxmox VE, right under QEMU/KVM.

The whole difference: the hypervisor is elsewhere

With QEMU/KVM, the hypervisor is the machine running the script. With Proxmox it is somewhere else, so the first question is which host — and the answer is remembered for the session. Three ways, all offered by the menu:

From the local QEMU VMs — a proxmox VM deployed here. Its address comes from the DHCP lease, nothing to retype.
By address — user@host, plus an optional SSH jump.
From ~/.ssh/config — the alias already carries user, port and ProxyJump; nothing else is asked.

The chosen host is then checked, not assumed: pveversion proves it is a Proxmox, id -u and sudo -n true decide whether commands need sudo, and an unknown SSH host key is offered for recording (with ssh-keyscan, never by disabling the check — a hypervisor is not a throwaway VM).

# Ce que l'outil envoie, et qu'on peut rejouer à la main :
ssh erplibre@pve1 sudo sh -c 'qm list'
ssh erplibre@pve1 sudo sh -c 'pvesm status --content images'

Why SSH and `qm`, not the REST API

The API needs a token or a ticket to create and renew. qm is the path every Proxmox administrator knows, the repository already manages SSH access (~/.ssh/config, ProxyJump, keys), and the commands stay readable in the log — so they can be replayed by hand. That is how every failure of this module was diagnosed.

sudo sh -c '<whole command>' and not sudo <command>: these commands are sequences and redirections. Prefixing with sudo would elevate only the first word, and the redirection would still be the unprivileged shell's.

Four traps met on a real host

A Proxmox installed on Debian has no vmbr0 — the ISO installer creates one, that procedure does not. And qm create requires a bridge.

The menu offers an internal bridge (vmbr0, 10.10.10.1/24, NAT through the uplink). Never adding the physical NIC to a bridge is deliberate: that moves the host address and cuts the SSH session in progress — remotely, there is no way back. A LAN-facing bridge is printed as a stanza to apply from a console.

On an internal bridge no DHCP answers, so the address is static, derived from the VMID — and therefore known before the VM boots. Looking for it afterwards was absurd.

The Debian cloud image does not ship qemu-guest-agent, so Proxmox cannot tell the address of a DHCP guest: it does not hand out the leases. The fallback is the host's own neighbour table (ip neigh), which needs nothing from the guest.

The seventeen QEMU/KVM entries have their counterpart. Four of them are the same code, because it is the same work: reopening the install monitoring, the remote desktop tunnel, the Android emulator and the image catalog. They reach Proxmox guests through the ~/.ssh/config entries that entry 13 writes, with the Proxmox host as ProxyJump.

[1] Déployer une VM        [8]  Redimensionner un disque   [15] Émulateur Android *
[2] Prévisualiser          [9]  Effacer des VM             [16] Catalogue d'images *
[3] Télécharger une image  [10] Nettoyer (orphelins)       [17] Exemple (dry-run)
[4] Rouvrir le suivi *     [11] Tester une VM (Odoo)       [18] Changer d'hôte
[5] Lister (qm list)       [12] Statistiques
[6] Adresse IP d'une VM    [13] Configuration SSH
[7] Console d'une VM       [14] Tunnel bureau distant *
                                        * code partagé avec le menu QEMU/KVM

Verified

Deploying a VM inside a Proxmox that itself runs in a libvirt VM: image downloaded on the host, internal bridge created, static address, cloud-init user and key, disk resized, qm start. Then ssh vm-essai from the outside reaches it through the jump — three nested levels. Resize 12G → 16G, delete with --purge, orphan scan: all checked against Proxmox VE 9.2.11.

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